A main beam support mounting bracket formed from aluminum for a vehicle. The main beam support mounting bracket has a first lateral end that is mechanically secured to a main beam support and a second lateral end that is mechanically secured to a center support. A bottom wall of the main beam support mounting bracket includes slotted mounting openings for receipt of fasteners for attachment to a floor tunnel of a vehicle floor and frame cross-member. The fasteners threadingly engage weld-nuts on the frame cross-member. The bottom wall includes first, second, and third planar surfaces that interact with first, second, and third surfaces of the floor tunnel in the vehicle. Further, the main beam support mounting bracket provides for lateral attachment with the main beam support and the center support.